Snap-in locking device for a multistage rotary switch

Abstract

The invention relates to a snap-in locking device for a multistage rotary switch with a switch spindle that is connectable with a rotary knob. The switch spindle is connected with an axle part that is snapped into an inner receptacle of a built-in switch panel part. The axle part rests on the switch panel part and is lock-in adjustable between snap-in receptacles with cams that are each limited by two radially-aligned connector links. The snap-in receptacles cover the entire circumference of the inner receptacle of the switch panel part. The axle part can be set into rotary motion with the switch spindle by a rotary knob, which is attachable to the switch spindle, and that modifiable limit stops define the number of switch positions, then a snap-in locking device for a operating unit is created with simple and cost-effective production and assembly parts that is coupleable with other components of the operating unit and can be equipped with an over-rotation safeguard.

We claim:  
     
       1. A snap-in locking device for a multistage rotary switch with a switch spindle that is connectable with a rotary knob, by means of which a switch part is adjustable into several switch positions, wherein the switch positions are determined by the pre-defined snap-in positions of the snap-in locking device, which comprises a snap-in lock element and counter-snap-in elements, 
       wherein  
       the switch spindle is connected with an axle part that is snapped into an inner receptacle of a built-in switch panel part,  
       that the axle part rests on the switch panel part and is lock-in adjustable between snap-in receptacles with cams that are each limited by two radially-aligned connector links,  
       that the snap-in receptacles extend around the entire circumference of the inner receptacle of the switch panel part,  
       that the axle part can be set into rotary motion with the switch spindle by means of a rotary knob, which is attachable to the switch spindle, and  
       that modifiable limit stops define the number of switch positions.  
     
     
       2. A snap-in locking device according to  claim 1 , 
       wherein  
       the switch spindle is designed as a one-piece plastic-injection mould part.  
     
     
       3. A snap-in locking device according to  claim 2 , 
       wherein  
       the axle part provides snap-in tabs that can be snapped into the inner receptacle of the switch panel part.  
     
     
       4. A snap-in locking device according to  claim 3 , 
       wherein  
       the inner receptacle of the switch panel part provides a localization receptacle and  
       that a sleeve of the axle part provides a locating catch for correct snap-in positioning of the axle part with the switch panel part and for alignment with limit stops of the switch panel part and limitation of the switch positions.  
     
     
       5. A snap-in locking device according to  claim 4 , 
       wherein  
       the axle part is likewise designed as a plastic-injection mould with the switch spindle and unlike the switch panel part, which consists of ABS, is made of POM.  
     
     
       6. A snap-in locking device according to  claim 5 , 
       wherein,  
       at least the front section of the switch spindle that protrudes out from the switch panel part has a non-circular profile and that the rotary knob, which can be slipped-on, features a notched tab receptacle for engagement with the front section.  
     
     
       7. A snap-in locking device according to  claim 6 , 
       wherein  
       the notched tab receptacle of the rotary knob is held in snug-fit or press-fit onto the front section of the axle part by means of a notched annular spring or the like.